Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
(n+1)((2(n+1)-1)(2(n+1)+1))/3 - (n(2n-1)(2n+1))/3
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
